Serena Williams was arguably the tennis story of 2012 as she went 58-4 and reeled in titles at Wimbledon, the US Open and the Olympics. In particular, the second half of the season was spectacular and it's no surprise to see her chalked up at 6/4 favourite in this market. However, it should be remembered that thanks to a ranking system which few seem to like, the American ended last season at only number three in the WTA list. The main reason for that was a costly first-round defeat at the French Open and Victoria Azarenka's consistency in reaching at least the semi-finals at three of the four Grand Slams. When you consider that Williams missed out last season when a) playing so well and b) being fit for virtually the entire year, you have to question whether 6/4 is good value. Azarenka is just behind in the betting at 7/4 with Maria Sharapova, last season's other Slam champion, at 9/2. However, the real value here would appear to lie with a big-priced outsider, namely Petra Kvitova. Think back 12 months (when the Czech was at the head of the market) and all the talk was of Kvitova being the number one in waiting. Instead it was Azarenka who picked up the baton and ran with it. My point is that Kvitova has the tools to challenge at the top of the game, as she showed in 2011 when she won Wimbledon and the season-ending WTA Championships. A tricky lefty serve and a big forehand are both serious weapons and I'd be very surprised to see Kvitova struggled like she did last season (she finished 'only' eighth in the rankings). Unlike last year, expectations are now much lower and, to a certain extent, the pressure will be off. With Kvitova offered at 33/1 - she's 12/1 elsewhere - a small punt may just pay handsome dividends.

To finish in the top eight

The value in this market would appear to lie with Russia's Nadia Petrova, who finished the 2012 campaign strongly to suggest she can contend for a top-eight spot this time around. With new coach Ricardo Sanchez having reinvigorated her game, Petrova thrashed Caroline Wozniacki in the season-ending event in Sofia, that success coming just weeks after back-to-back wins over top-10 stars Sara Errani, Sam Stosur and Agnieszka Radwanska carried her to the Tokyo title. Victories of that calibre are the kind which will take you into the elite eight - Petrova also pushed Maria Sharapova to 6-4 in the third at the US Open - so the 7/2 about the Russian improving four places on her 2012 ranking has to be considered. Petrova, who ended 2012 looking even higher and targeting Grand Slam victories, is one of the female players who can really play on clay too. Her main weakness over the years has been staying completely fit and healthy but that wasn't a problem last season, while her age, 30, should not be a concern with the likes of Serena Williams, Li Na and Francesca Schiavone showing in recent times that age is no barrier to success. In short, the bet looks worth a try.

Under/over ranking

Christina McHale looks the value in Sky Bet's list. The American is 5/6 to finish above or below the 32.5 line and I feel she's more than capable of finishing higher in the rankings. McHale had wins over Kvitova and Caroline Wozniacki during a decent first half of last season, one which saw her climb as high as 24th in the ranking list. A nightmare second half followed as she was struck down by glandular fever and didn't win a match after Montreal in August. Despite that she still finished 33rd. Of course, the question which remains to be answered is has she fully recovered? Recent practice in Miami is a good sign and she has a full schedule planned Down Under in January. With the illness doubt still hanging over her, it's probably wise not to go overboard, but if recovery has been good, it's easy to see McHale finishing well inside the top 30.

The second selection in this market is Andrea Petkovic, another player on her way back after a long spell on the sidelines. This time last year the German sat 10th in the ranking list after a highly impressive 2011 which brought three Grand Slam quarter-finals. But last season she suffered not one but two serious injuries (back then ankle) and played little tennis. However, Petkovic is a talented performer and also a fighter, so she's a player of which plenty can be expected in 2013, relapses excepted. Certainly she ended 2012 well, defeating Jelena Jankovic en route to the last four in Luxembourg where she pushed Venus Williams all the way. Then came a run to the last four of a smaller tournament in Pune. sportingbet offer 6/4 about her finishing in the top 20 which is very tempting (Sky Bet at are 5/6).

The main concerns here regard fitness - if both are 100 per cent recovered then the bets should come in. However, with the questions marks hanging around, I've designed a staking plan which will result in a profit if just one of the two comes in and suggest you do likewise.